From a4261598be7e3229a6280002eaced96d8cb3ced6 Mon Sep 17 00:00:00 2001
From: Yong He <yonghe@outlook.com>
Date: Wed, 23 Jan 2019 19:54:21 -0800
Subject: Fixing GLSL sign function.

fixes #602
---
 source/slang/emit.cpp               | 21 +++++++++++++++++++--
 tests/cross-compile/sign.slang      | 13 +++++++++++++
 tests/cross-compile/sign.slang.glsl | 17 +++++++++++++++++
 tests/cross-compile/sign.slang.hlsl |  6 ++++++
 4 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 tests/cross-compile/sign.slang
 create mode 100644 tests/cross-compile/sign.slang.glsl
 create mode 100644 tests/cross-compile/sign.slang.hlsl

diff --git a/source/slang/emit.cpp b/source/slang/emit.cpp
index 0aebf6153..914aea7fd 100644
--- a/source/slang/emit.cpp
+++ b/source/slang/emit.cpp
@@ -3488,7 +3488,23 @@ struct EmitVisitor
             emit(".");
             operandIndex++;
         }
-
+        // fixing issue #602 for GLSL sign function: https://github.com/shader-slang/slang/issues/602
+        bool glslSignFix = ctx->shared->target == CodeGenTarget::GLSL && name == "sign";
+        if (glslSignFix)
+        {
+            if (auto vectorType = as<IRVectorType>(inst->getDataType()))
+            {
+                emit("ivec");
+                emit(as<IRConstant>(vectorType->getElementCount())->value.intVal);
+                emit("(");
+            }
+            else if (auto scalarType = as<IRBasicType>(inst->getDataType()))
+            {
+                emit("int(");
+            }
+            else
+                glslSignFix = false;
+        }
         emit(name);
         emit("(");
         bool first = true;
@@ -3499,7 +3515,8 @@ struct EmitVisitor
             first = false;
         }
         emit(")");
-
+        if (glslSignFix)
+            emit(")");
         maybeCloseParens(needClose);
     }
 
diff --git a/tests/cross-compile/sign.slang b/tests/cross-compile/sign.slang
new file mode 100644
index 000000000..17a51d93d
--- /dev/null
+++ b/tests/cross-compile/sign.slang
@@ -0,0 +1,13 @@
+// sign.slang
+
+//TEST:CROSS_COMPILE:-target spirv-assembly -entry main -stage fragment
+//TEST:CROSS_COMPILE:-target dxil-assembly  -entry main -stage fragment -profile sm_6_0
+
+// Test cross compilation of the sign function
+
+float4 main() : SV_Target
+{
+    float4 s = sign(float4(1.5, 1.0, -1.5, -1.0));
+    return s;
+}
+
diff --git a/tests/cross-compile/sign.slang.glsl b/tests/cross-compile/sign.slang.glsl
new file mode 100644
index 000000000..7a3a37c51
--- /dev/null
+++ b/tests/cross-compile/sign.slang.glsl
@@ -0,0 +1,17 @@
+//TEST_IGNORE_FILE:
+#version 450
+layout(row_major) uniform;
+layout(row_major) buffer;
+
+#line 8 0
+layout(location = 0)
+out vec4 _S1;
+
+
+#line 8
+void main()
+{
+    ivec4 _S2 = ivec4(sign(vec4(1.50000000000000000000, 1.00000000000000000000, -1.50000000000000000000, -1.00000000000000000000)));
+    _S1 = vec4(_S2);
+    return;
+}
\ No newline at end of file
diff --git a/tests/cross-compile/sign.slang.hlsl b/tests/cross-compile/sign.slang.hlsl
new file mode 100644
index 000000000..d7016dde7
--- /dev/null
+++ b/tests/cross-compile/sign.slang.hlsl
@@ -0,0 +1,6 @@
+//TEST_IGNORE_FILE:
+float4 main() : SV_Target
+{
+    float4 s = sign(float4(1.5, 1.0, -1.5, -1.0));
+    return s;
+}
\ No newline at end of file
-- 
cgit v1.2.3